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consolidate parameters, add comment (#102)

* updates

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* code review of nla_intervals: combine functionality

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* tidy

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* formatting

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* add comments

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* merge issue

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* tired of looking at compiler warning

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2019-12-17 08:24:30 -08:00 committed by Lev Nachmanson
parent 580f229a16
commit 0535e24dd1
5 changed files with 72 additions and 48 deletions

View file

@ -24,15 +24,15 @@ using namespace nla;
grobner::grobner(core *c, intervals *s)
: common(c, s),
m_gc(m_nex_creator,
c->m_reslim,
c->m_nla_settings.grobner_eqs_threshold(),
c->m_nla_settings.grobner_expr_size_limit()
),
m_gc(m_nex_creator, c->m_reslim),
m_look_for_fixed_vars_in_rows(false) {
std::function<void (lp::explanation const& e, std::ostream & out)> de;
de = [this](lp::explanation const& e, std::ostream& out) { m_core->print_explanation(e, out); };
grobner_core::params p;
p.m_expr_size_limit = c->m_nla_settings.grobner_expr_size_limit();
p.m_grobner_eqs_threshold = c->m_nla_settings.grobner_eqs_threshold();
m_gc = de;
m_gc = p;
}
void grobner::grobner_lemmas() {
@ -183,6 +183,22 @@ void grobner::add_row(unsigned i) {
/// -------------------------------
/// grobner_core
/***
The main algorithm maintains two sets (S, A),
where S is m_to_superpose, and A is m_to_simplify.
Initially S is empty and A contains the initial equations.
Each step proceeds as follows:
- pick a in A, and remove a from A
- simplify a using S
- simplify S using a
- for s in S:
b = superpose(a, s)
add b to A
- add a to S
- simplify A using a
*/
bool grobner_core::compute_basis_loop() {
while (!done()) {
if (compute_basis_step()) {
@ -205,20 +221,22 @@ bool grobner_core::compute_basis_step() {
}
m_stats.m_compute_steps++;
simplify_using_to_superpose(*eq);
if (equation_is_too_complex(eq))
return false;
if (!canceled() && simplify_to_superpose_with_eq(eq)) {
TRACE("grobner", tout << "eq = "; display_equation(tout, *eq););
superpose(eq);
if (equation_is_too_complex(eq)) {
TRACE("grobner", display_equation(tout, *eq) << " is too complex: deleting it\n;";);
del_equation(eq);
} else {
insert_to_superpose(eq);
simplify_m_to_simplify(eq);
TRACE("grobner", tout << "end of iteration:\n"; display(tout););
}
if (!simplify_to_superpose_with_eq(eq)) {
return false;
}
TRACE("grobner", tout << "eq = "; display_equation(tout, *eq););
superpose(eq);
if (equation_is_too_complex(eq)) {
TRACE("grobner", display_equation(tout, *eq) << " is too complex: deleting it\n;";);
del_equation(eq);
return false;
}
insert_to_superpose(eq);
simplify_m_to_simplify(eq);
TRACE("grobner", tout << "end of iteration:\n"; display(tout););
return false;
}
@ -241,6 +259,26 @@ grobner_core::equation* grobner_core::pick_next() {
return r;
}
void grobner_core::simplify_using_to_superpose(equation& eq) {
bool simplified;
TRACE("grobner", tout << "simplifying: "; display_equation(tout, eq); tout << "using equalities of m_to_superpose of size " << m_to_superpose.size() << "\n";);
do {
simplified = false;
for (equation* p : m_to_superpose) {
if (simplify_source_target(*p, eq)) {
simplified = true;
}
if (canceled() || eq.expr()->is_scalar()) {
break;
}
}
} while (simplified && !eq.expr()->is_scalar());
TRACE("grobner",
if (simplified) { tout << "simplification result: "; display_equation(tout, eq); }
else { tout << "no simplification\n"; });
}
grobner_core::equation_set const& grobner_core::equations() {
m_all_eqs.reset();
for (auto e : m_to_simplify) m_all_eqs.insert(e);
@ -279,29 +317,7 @@ void grobner_core::del_equation(equation * eq) {
SASSERT(m_equations_to_delete[eq->m_bidx] == eq);
m_equations_to_delete[eq->m_bidx] = nullptr;
dealloc(eq);
}
void grobner_core::simplify_using_to_superpose(equation& eq) {
bool simplified;
TRACE("grobner", tout << "simplifying: "; display_equation(tout, eq); tout << "using equalities of m_to_superpose of size " << m_to_superpose.size() << "\n";);
do {
simplified = false;
for (equation* p : m_to_superpose) {
if (simplify_source_target(*p, eq)) {
simplified = true;
}
if (canceled() || eq.expr()->is_scalar()) {
break;
}
}
}
while (simplified && !eq.expr()->is_scalar());
TRACE("grobner",
if (simplified) { tout << "simplification result: "; display_equation(tout, eq);}
else {tout << "no simplification\n";});
}
}
const nex* grobner_core::get_highest_monomial(const nex* e) const {
switch (e->type()) {
@ -725,7 +741,7 @@ bool grobner_core::canceled() {
}
bool grobner_core::done() {
return num_of_equations() >= m_grobner_eqs_threshold || canceled();
return num_of_equations() >= m_params.m_grobner_eqs_threshold || canceled();
}
void grobner_core::del_equations(unsigned old_size) {

View file

@ -38,6 +38,11 @@ struct grobner_stats {
class grobner_core {
public:
struct params {
unsigned m_grobner_eqs_threshold;
unsigned m_expr_size_limit;
};
class equation {
unsigned m_bidx; //!< position at m_equations_to_delete
nex * m_expr; // simplified expressionted monomials
@ -88,16 +93,14 @@ private:
nex_lt m_lt;
bool m_changed_leading_term;
equation_set m_all_eqs;
unsigned m_grobner_eqs_threshold;
unsigned m_expr_size_limit;
params m_params;
public:
grobner_core(nex_creator& nc, reslimit& lim, unsigned eqs_threshold, unsigned expr_size_limit) :
grobner_core(nex_creator& nc, reslimit& lim) :
m_nex_creator(nc),
m_limit(lim),
m_dep_manager(m_val_manager, m_alloc),
m_changed_leading_term(false),
m_grobner_eqs_threshold(eqs_threshold),
m_expr_size_limit(expr_size_limit)
m_changed_leading_term(false)
{}
~grobner_core();
@ -112,6 +115,7 @@ public:
std::ostream& display(std::ostream& out) const;
void operator=(print_expl_t& pe) { m_print_explanation = pe; }
void operator=(params const& p) { m_params = p; }
private:
bool compute_basis_step();
@ -160,7 +164,7 @@ private:
std::ostream& print_stats(std::ostream&) const;
std::ostream& display_dependency(std::ostream& out, common::ci_dependency*) const;
bool equation_is_too_complex(const equation* eq) const {
return eq->expr()->size() > m_expr_size_limit;
return eq->expr()->size() > m_params.m_expr_size_limit;
}
#ifdef Z3DEBUG
bool test_find_b_c(const nex* ab, const nex* ac, const nex_mul* b, const nex_mul* c);

View file

@ -5,6 +5,7 @@
namespace nla {
typedef intervals::interval interv;
typedef enum intervals::with_deps_t e_with_deps;

View file

@ -293,6 +293,7 @@ public:
if (wd == with_deps) {
i.m_lower_dep = a.m_lower_dep;
}
}
template <enum with_deps_t wd>
@ -313,8 +314,10 @@ public:
}
template <enum with_deps_t wd>
bool interval_from_term(const nex& e, interval& i) const;
template <enum with_deps_t wd>
interval interval_of_sum_no_term(const nex_sum& e);

View file

@ -2171,7 +2171,7 @@ public:
for(const nla::lemma & l : lv) {
m_lemma = l; //todo avoid the copy
m_explanation = l.expl();
m_stats.m_nla_explanations += l.expl().size();
m_stats.m_nla_explanations += static_cast<unsigned>(l.expl().size());
false_case_of_check_nla();
}
break;